The following relates to the fluid flow processing arts, mass transport arts, electro-osmotic, electrophoresis, and electrokinetic device arts, and related arts.
Electrokinetics relates to electrically driven mass transport, and is of technological importance in various forms. One electrokinetic process is the electrically driven flow of a fluid with respect to a solid surface, referred to as electro-osmosis. Another electrokinetic process is the electrically driven transport of particles in fluids, referred to as electrophoresis. A necessary condition of electrokinetics is separation of electric charges in space. Once separated, these charges can be carried by an applied electric field, thus producing electro-osmosis or electrophoresis.
A known approach for achieving charge separation at a solid-fluid interface is through dissociation of molecular groups and the formation of electric double layers. Another approach is to separate charges by the applied electric field, but this is applicable only to highly polarizable solid components. In an isotropic electrolyte fluid, the solid component mediates separation of charges, and the fluid supplies counterions to complete the double layer buildup.
These approaches have substantial disadvantages. For example, to achieve electrophoresis by these mechanisms the transported particles must be polarizable, e.g. an ionic compound such as a salt that can be separated into cation and anion components. This limits the range of particles that can be subjected to electrophoresis by these mechanisms in terms of surface charge magnitude, polarizability, shape asymmetry, and other properties.